Part 2: Causes of Eye Strain

Eye strain is caused by fatigue of the one or more muscles surrounding the eye. (Refer to Week #1 What is Eye Strain). The muscle is strained or fatigued because it is in one position for too long. It is synonymous to holding your arms up at 90˚ for longer than 5 minutes. All muscles fatigue, and it is no different for your eyes. Concentrating on something for too long, like a computer screen or a television will cause the muscles controlling the eye to fatigue.

An easy way to help reduce the fatigue rate of the eye muscles is to remember the “20-20-20 rule”, which states that for every 20 minutes, take a break from the computer and focus on something other than the television or computer at least 20 feet away for 20 seconds, just to relax the muscles.

This ergo-tip is a part of an ergo-tip series about musculoskeletal injuries. Please visit the table of contents at for other available posts. There will be one post released every Tuesday.